1. Field of the Invention
The present invention relates to polyformal and polycarbonate copolymers which are useful as surfactants. More specifically, individual blocks of polymers and copolymers of alkylene oxides are reacted with either a lower dialkyl carbonate or formaldehyde to form blocks linked by formal or carbonate groups.
2. Prior Art
Surface active multi-block polyoxyalkylene copolymers are well known in the art. This is evidenced by the teachings of U.S. Pat. No. 2,950,310 wherein esters are produced from polyoxyalkylene glycols, dibasic acids and monohydric alcohols. The dibasic acids contain from 2 to 12 carbons. There is no teaching of the particular surface active compounds of this invention. The coupling compounds employed in the present invention contain only one carbon atom. Further, there is no teaching of the use of multi-block coupling such as taught by the present invention.
U.S. Pat. No. 2,905,719 teaches the preparation of surface active formals whereby an alkyl group is linked to a polyoxyethylene group through a formal linkage. There is no teaching of the use of multiple formal linkages joining multi-block polyoxyalkylene groups. Further, the present invention does not link an alkyl group to a polyoxyalkylene group. The present invention is directed to linking blocks of polyoxyalkylene groups to one another.